The assembly of the present invention may be adapted primarily for use to separate particulates or sediment suspended in a liquid medium, such as in water and wastewater treatment processes. However, the present assembly may also be adapted for use as heat transfer media or contact bodies, for example in an evaporative-type heat exchange apparatus, as fill for gas scrubbers for reducing air pollution, and as other surface media for use in trickling filters for water treatment, air scrubbing or stripping equipment. This invention will be explained herein with reference to its primary intended use as to separate particulates and sediment from water in water and wastewater treatment processes. An assembly used for this purpose is generally referred to as a tube settler.
The selection of a method for removing impurities from wastewater depends upon the nature of the pollutants or undesirable contaminants present. Major contaminants in wastewater include: (1) suspended solids; (2) greases and oils; (3) organic matter; (4) dissolved metals; and (5) toxic chemicals. Large suspended solids and trash may be removed from water by screening devices. Suspended solid particles may be removed from a stream by gravitational settling or sedimentation.
The device of the present invention is particularly suited to provide an environment wherein suspended solids may be removed from a stream by gravitation settling or sedimentation. The device of the present invention may also advantageously be used as a contact body to promote the intimate mixture of and heat exchange between two counter-flowing or cross-flowing fluid streams. The device of the present invention may also find use as a contact body for promoting the intimate contact of gas and liquids. Yet another use for the device of the present invention is as an artificial reef for marine environments.
The prior art discloses many different contact bodies assembled from alternating generally planar sheets and corrugated sheets. The prior art also discloses many different contact bodies formed by stacking a single sheet having various configurations.
U.S. Pat. No. 5,217,788 discloses an assembly made from a plurality of generally parallel corrugated contact sheets. The sheets have generally planar positioner pads positioned at least at some of the intersections formed by the apices of adjacent sheets coming together. The apices have indented portions between each positioner pad.
U.S. Pat. No. 4,800,047 discloses an assembly of trickling sheets of rectangular form for a packing means for an installation used for bringing into contact a liquid and a gas flowing in a counter-current manner, where each sheet is characterized as comprising a first zone which is greatly corrugated and a second zone which is slightly corrugated or flat. The sheets contain spacer bosses. Upon stacking the sheets in a specified manner, the resulting assembly is a packing element with rectilinear channels.
U.S. Pat. No. 4,668,443 discloses improved gas liquid contact sheets and contact bodies formed from a plurality of those contact sheets, where the improvement comprises having positioner pads positioned in apices of the corrugations of the contact sheets such that at least about eighty percent of the intersections of adjacent sheets contain abutting pairs of the positioner pads.
U.S. Pat. No. 2,160,677 discloses a corrugated sheet with corrugations of a trapezoidal cross-section, where the side walls of the corrugations are reinforced through additional or transverse corrugations extending at right angles to the main or longitudinal corrugations. The transverse corrugations impart a zig-zag outline to the edges of a plane forming the top or bottom of the trapezoidal corrugations.
U.S. Pat. No. 2,091,918 discloses an insulating material comprising a corrugated sheet and a planar lining sheet, where the lining sheet has indentations or depressions which are complementary to the apices of the corrugated sheets and cause the lining to interengage with the crowns of the corrugations. In this way, the employment of paste or other adhesive to join the lining and corrugated sheets is eliminated.
Several U.S. patents disclose assemblies, and/or processes for making assemblies, comprising alternating corrugated and planar sheets, e.g., U.S. Pat. Nos. 3,265,550, 3,099,696, 3,048,918, 2,986,379, and 2,809,918.
Compared to the prior art, the present invention provides a contact body particularly suited as a tube settler for wastewater treatment, and having superior manufacturing ease and performance as a tube settler.